Securing of a member to a support by means of a spring



J. WIJCHMAN Dec. 15, 1953 SECURING OF A MEMBER TO A SUPPORT BY MEANS OF A SPRING Filed Feb. 24, 1950 Patented Dec. 15, 1953 OF A MEMBER TO A sU P a'r n ME NS: O A I GS Jan Wiiehmani Eindhoven, Netherlands, assignor to Hartfiord National Bank and Trust Company, flwfvs a e Application- February 24, 1956', Serial No. 12453998 priority, application Neflier-lands Match 19 9. M

I (Cl. 267-21) 1 This inventionrelates to the-securing ota member'to'a support by-meansora spring;

l The object ofthe invention is DIQY-ide' a cheap and compact'hianner' of securing; asxnall member to a tripartit example the pick up head of a gramophone to a pick-up arm. The invention ma rmb'r has for objects to enable the securingoperatior' tobe carried out in l easy way. to pl verlt thfi'afliqqhment from loosen-- ing clue to vibration andto render-it particularly suitable for use, in cnstructiom' ma uf u ed by a moulding of die-casting process;

Accordingtothe mtnaon the combination: of a member and a s zcrt the e he beng S curedin a recess of the support by meansof at leastonesprifig, 15* characterised in that use is made ofat'least 'o" helical or spiral spring, of eachef vlhiclithe end (the clanmin gendf) in the direction of longitudinal axis exerts pres sure on the member secured, and the other end (the anchored end), which is provided with a lateral extension; bears with this: extension in a depression of the supportjthe arrangementbeing such that meme; ends-ofthe compressed and twisted spring are loclid' against relaxation in the axial? and tangen in directions; and against lateral'shif-t.

l he sole part required; addition to thegmen her and the support "is a spring, which can be mass 'manuf acturedjn a very cheap' nanner. The:

additional costof slj ping. the: support and, if necessary; o'f-"thenle'gnber are practicallynegl'igible for membersinou dedi'n hulk Attachment may-be efliec'ted very'i'apidly' and thus also in volves little cost; 'I'liesprmgcanno tbecome'loose due to vibration, but it can readily be removed and-replaced;

At least part of each; spring adjacent one ex; tremity is pre f'erably'locked against lateral shift in that atleast this-partbearsin a suitable recess of 'thesupportzon'of-the member. More partioularly.--in;the. case of a moulded support, this recess-z can readily beprovided. Irrthis case;

the member; is: preferably: provided with, for' ex ample, two rod-shaped: extensions, which in cer'-'--- tain; cases. for example; thecase ofa shaft. already are present, while the-said recess-of the support is acylindrical cavity extending in the direction in-whicliitliem'oulding ordie castin'g is removed from the rnatr ix (moulding direction) and having a slot in the surface of the support,

the-slot extending panallelito the longitudinal axis of the cavity and allowing the said extensionaccessitostheacavityi.

Im a. furthen embodiment: a spring or part thereoisurroundsa majnd ril; formed on themeniber'or on the sup ort and prevents a lateral shift of the spring or' of atleast one of its ends v In order that the inventionniay b more clearly understood and readily carried into efiect, it will now be described more fully with reference to the accompanying diagrammatic drawing.

Fig; 1- is a'perspective view of the device em bodying the present invention.

Fig. 2 shows an auxiliary tool suitablefor co n pressing and twisting a spring of the type em-7 ployed'with the presenti-nvention.

Fig. 3' is a sectionalview taken on the finest-Z1!- of Fig. 4 showing a Modification of the device*'e'm-- bod yi'ng the presentinvention.

Fig. 4 iSf a sectional view taken; along the lines 4lof Fig.3. V

Fig. 5' a perspective view ofanothe'r embodi: mentof the'presentinvention Referring now to Fijgi I, which is a perspective view, a shaft for 'a rope disc is secured to the cabinet consisting of moulded-material of a radio receiver. On the innerside'of one cabinet wall 3, "the walls each extending parallel to. the moulding direction (vertical in the drawingfiis formed an elevation 5* which extends to the bottom 1: of the" cabinet The elevation 5 15pmvide'd with a cylindrical cavity 9 (the arrow (if the reference nuineral indicates the longitudinal axisof the cavitw-"which accommodates a helical spring; H. A slotlathelongitudinafdirection of which is parallel to the longitudinal" axis of,

the'cavity isprovidedin the elevation 5" to enable the (ind of the start If tiofbeseculed to be in- 1 serted' into the" cavity '9 "The elevation S hasa re-entrant "part 5" in which a slot [5, is milled" parallel to the-bottomlfy At the lowerendofthe shaft 1' ('clampingend) thespring ("F has an axialextension llai' whi'c'li laterallyengagesthe shaft 'l, whereas the other end of" the-sprihg'i's'" provided with a lateral ex tension!l-b-(heretangential);

The sprin g H isfi ht'lfodu ced intoicavityfl; and then compressed and sliglitly twisted, for exainw ple; bymeanso fthe tool shown'in Fig 2 or'inanually the eXtensionli-U peiii moved" (as viewed from above'l' ina c l'qclgwise direction. After re, lease; th'eextension l'lb' clicks into the slot" l5 and is then anchored against'further relaxation.

by turning in the anti-clockwise direction. and also against relaxation time axialldirectiomii 'e; in the longitudinal "d ec tion ofthe sl'ot19f Eurtherxnore; the top end of'thespring l .I i s su p ported by'thefwall ofithe cavity a, againstlateraL shift, 56 that'this wall 'a'bso'rb's the reaction or? me /res 3 the force exerted in the horizontal direction by the extension Mb- The lower end of the spring clamping the shaft l is locked against rotation in the direction of relaxation, since the extension ||a bears against the shaft the axial force is effectively used for securing the attachment end of the shaft I while lateral shift, as before, is prevented by the walls of the cavity 9.

It will be seen that the shaft is thus secured so as to be free from play with the use of a single very simple resilient member which can readily be arranged, which does not become loose due to vibration, but which can readily be removed. The other end of the shaft I may be secured in an exactly similar manner to the wall of the moulded cabinet opposite the wall 3, since it is possible to insert the shaft from above through the two slots l3 into the two cavities 9. The elevation 5, together with the cavity 9 and the slot l3, may be formed during the operation of moulding the cabinet 3, 1, with little additional cost, and the slot is provided by a simple milling operation, which also involves little increase in cost.

Figs. 3 and 4 are two cross-sectional views taken at right angles to one another along the lines IIIIII and IVIV, respectively, of a gramophone pick-up head in which use is made of two sapphire needles adapted to be used alternately. Such pick-up heads permit of playing two kinds of records, for example records to be played at a speed of '78 revs/min. and records to be played at a speed of 33 revs/min.

The pick-up head comprises a piezo-crystal having two sapphire needles 2| and 23 arranged at an angle with each other and apart from the needles, is contained in an elongated box 25 of moulded material. This box is arranged to be pivotal through a limited angle in a housing 21 provided at the end of a pick-up arm (not shown) The box 25 is rotatable about its longitudinal axis in a manner such that the two needles 2| and 23 may alternately be brought into the operating position.

The housing 21 is substantially semi-circular in section (Fig. 4) and the cross-section of the box 25 has a suitable circular part. Formed at each end (only one is shown in detail) of the box 25 is an axial elevation 29, which is urged by a conical spiral spring 3| against the cylindrical inner wall of the housing 21. The elevation 29 may be shifted along this wall, the box 25 then rotating about its longitudinal axis, but the freedom of movement is restricted in that the elevation 29 is provided in a rectangular space 33, formed between locally thickened walls 21a and 21b of the housing 21. Since midway between the walls 21a and 211) a rib 35 is formed on the inner wall of the housing 21, the elevation 29, as is shown in Fig. 4, may occupy either of two preset positions, in which either of the two needles 2| and 23 is vertical when viewed as in Fig. 4.

The walls 21a and 2112 (primarily the latter in the case shown) support the anchored end of a compressed and twisted spring 3| (the base of the cone) against lateral shift in co-operation with the terminal wall of the box 25. At the other end (attachment end) of the spring 3|, this function is fulfilled in that the spring is provided about a projecting mandril 31, (this is conical in the case shown) on the elevation 29.

In order to avoid relaxation of the spring 3|, the attachment end and the anchored end are provided, in a manner similar to that shown in 4 Fig. 1, with an axial extension 3|a and a lateral extension 3|b, respectively. The former bears against the elevation 29, the latter lies in a slot 4| provided in the terminal wall of the housing 21.

The box 25 and the housing 21 are both capable of being moulded (the slot 4| is provided by a milling operation) so that they can be made at low cost. The spring 3| is conical, in order to permit the desired freedom of movement of the elevation 29 and the attachment end of the spring between the walls 21a and 21b.

It is obvious that the construction shown in Figs. 3 and 4 may, as an alternative, be used for securing a member in one fixed position, in a manner similar to that shown in Fig. 1.

Fig. 5 shows an embodiment in which a gramophone pick-up head 5| is housed in a cup'shaped support 53 by means of two helical springs 55 (one is visible in Fig. 5) each of which surrounds a cylindrical mandril 51 projecting from the head 5|. Each mandril 51 supports the two ends of the associated spring 55 against lateral shift. The spring is locked against relaxation, as may be seen from Fig. 5, in a manner similar to that shown in Fig. 1 and Figs. 3 and 4.

It is obvious that the attachment shown in Fig. 5 may also be used in the pick-up head shown in Figs. 3 and 4. It will furthermore be evident that in Fig. 5 the mandril 51 may, as desired, be formed on the bottom of the box 53 and may be replaced by a recess in the part 5| into which the spring 55 fits, while other combinations are also possible.

An important advantage of the attachment described is that it may also be used with thermoplastic die-casting or moulding material, since with the use of this material screw fastening is in practice unserviceable, since screws in this material ultimately become loose.

What I claim is:

1. A combination of member and support, a recess in said support, means to secure said member in said recess, said means comprising a coil spring located within the walls of said recess, said spring having a clamping end disposed directly against said member to exert pressure in the direction of its longitudinal axis, the other end of said spring having a lateral extension which is disposed in a depression in said support to anchor said spring to said support, the compression and torsional forces thus set up in said spring locking the ends of said spring against relaxation in the axial and tangential direction, and the walls of the recess preventing lateral shifting of the spring.

2. A combination of member and support, a recess in said support, means to secure said member in said recess, said means comprising a coil spring located within the walls of said recess, said spring having a clamping end disposed directly against said member to exert pressure in the direction of its longitudinal axis, a mandril projecting from said member, the other end of said spring surrounding said mandril and having a lateral extension which is disposed in a depression in said support to anchor said spring to said support, the compression and torsional forces thus set up in said spring locking the ends of said spring against relaxation in the axial and tangential direction, the walls of the recess and said mandril preventing lateral shifting of the spring.

3. A combination of member and support, said support being made of moulded material, a cylindrical cavity in said support, said cavity having its longitudinal axis extending in the moulding direction, the wall of said cavity being formed with a slot parallel to said longitudinal axis through which the member is introduced into said cavity, means to secure said member in said cavity, said means comprising a coil spring located within the walls of said cavity, said spring having a clamping end disposed directly against said member to exert pressure in the direction of its longitudinal axis, the other end of said spring having a. lateral extension which is disposed in a depression in said support to anchor said spring to said'support, the compression and torsional forces thus set up in said spring locking the ends of said spring against relaxation in the axial and tangential direction, and the walls of the cavity preventing lateral shifting of the spring.

4. A combination of member and support, said support being made of moulded material, a cylindrical cavity in said support, said cavity having its longitudinal axis extending in the moulding direction, the wall of said cavity being formed with a slot parallel to said longitudinal axis through which the member is introduced into said cavity, means to secure said member in said cavity, said means comprising a coil spring located within the walls of said cavity, said spring having a clamping end which is provided with a substantially axial extension disposed directly against that part of said member which is in said cavity to exert pressure in the direction of its longitudinal axis, the other end of said spring having a lateral extension which is disposed in a depression in said support to anchor said spring to said support, the compression and torsional forces thus set up in said spring locking the ends of said spring against relaxation in the axial and tangential direction, and the walls of the cavity preventing lateral shifting of the spring.

5. A combination of member and support, a recess in said support, means to secure said member in said recess in either of two positions, said means comprising a spiral spring located within the walls of said recess, the base of said spring having a diameter substantially the same as the recess, said spring having a clamping end at its top end disposed directly against said member to exert pressure in the direction of its longitudinal axis, the base of said spring having a lateral extension which is disposed in a depression in said support to anchor said spring to said support, the compression and torsional forces thus set up in said spring locking the ends of said spring against relaxation in the axial and tangential direction, and the walls of the recess preventing lateral shifting of the spring.

6. A combination of member and support, a recess in said support, a cavity in said member, a mandril positioned in said cavity and projecting therefrom, a coil spring surrounding said mandril having one end disposed directly against said member to exert pressure in the direction of the longitudinal axis of said member, the other end of said spring having a lateral extension positioned in said recess, the compression, and torsional forces thus set up in said spring against relaxation in the axial and tangential direction, the walls of said cavity and said mandril preventing-lateral shifting of said spring.

7. A combination of member and support, a recess in said support, means to secure said member against movement in said recess, said means including a coil spring in said recess having a clamping end disposed directly against said member to exert clamping pressure in the direction of its longitudinal axis, the other end of said spring having a lateral extension which is disposed in a depression in said support to anchor said spring to said support, the compression and torsional forces thus set up in said spring locking the ends of said spring against relaxation in the axial and tangential direction, and the walls of the recess preventing lateral shifting of the spring.

JAN WIJCHMAN.

References Cited in the file of this patent Colwell Nov. 22, 1949 

